drm/i915: Unify power well ID enums

Atm, the power well IDs are defined in separate platform specific enums,
which isn't ideal for the following reasons:
- the IDs are used by helpers like lookup_power_well() in a platform
  independent way
- the always-on power well is used by multiple platforms and so needs
  now separate IDs, although these IDs refer to the same thing

To make things more consistent use a single enum instead of the two
separate ones, listing the IDs per platform (or set of very similar
platforms like all GEN9/10). Replace the separate always-on power
well IDs with a single ID.

While at it also add a note clarifying the distinction between regular
power wells that follow a common programming pattern and custom ones
that are programmed in some other way. The IDs for regular power wells
need to stay fixed, since they also define the request and state HW flag
positions in their corresponding power well control register(s).

v2:
- Add comment about id to req,status bit mapping to the enum. (Rodrigo)

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170711204236.5618-1-imre.deak@intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 28 insertions, 14 deletions

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index c0199f2da35e..aee40eecf688 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -1063,9 +1063,20 @@ static inline bool i915_mmio_reg_valid(i915_reg_t reg)
 #define   DP_SSS_RESET(pipe)			_DP_SSS(0x2, (pipe))
 #define   DP_SSS_PWR_GATE(pipe)			_DP_SSS(0x3, (pipe))
 
-/* See the PUNIT HAS v0.8 for the below bits */
-enum punit_power_well {
-	/* These numbers are fixed and must match the position of the pw bits */
+/**
+ * i915_power_well_id:
+ *
+ * Platform specific IDs used to look up power wells and - except for custom
+ * power wells - to define request/status register flag bit positions. As such
+ * the set of IDs on a given platform must be unique and except for custom
+ * power wells their value must stay fixed.
+ */
+enum i915_power_well_id {
+	/*
+	 * VLV/CHV
+	 *  - PUNIT_REG_PWRGT_CTRL (bit: id*2),
+	 *    PUNIT_REG_PWRGT_STATUS (bit: id*2) (PUNIT HAS v0.8)
+	 */
 	PUNIT_POWER_WELL_RENDER			= 0,
 	PUNIT_POWER_WELL_MEDIA			= 1,
 	PUNIT_POWER_WELL_DISP2D			= 3,
@@ -1080,13 +1091,11 @@ enum punit_power_well {
 	/*  - custom power well */
 	CHV_DISP_PW_PIPE_A,			/* 13 */
 
-	/* Not actual bit groups. Used as IDs for lookup_power_well() */
-	PUNIT_POWER_WELL_ALWAYS_ON,
-};
-
-enum skl_disp_power_wells {
-	/* These numbers are fixed and must match the position of the pw bits */
-	SKL_DISP_PW_MISC_IO,
+	/*
+	 * GEN9+
+	 *  - HSW_PWR_WELL_DRIVER (status bit: id*2, req bit: id*2+1)
+	 */
+	SKL_DISP_PW_MISC_IO = 0,
 	SKL_DISP_PW_DDI_A_E,
 	GLK_DISP_PW_DDI_A = SKL_DISP_PW_DDI_A_E,
 	CNL_DISP_PW_DDI_A = SKL_DISP_PW_DDI_A_E,
@@ -1105,13 +1114,18 @@ enum skl_disp_power_wells {
 	SKL_DISP_PW_1 = 14,
 	SKL_DISP_PW_2,
 
-	/* Not actual bit groups. Used as IDs for lookup_power_well() */
-	SKL_DISP_PW_ALWAYS_ON,
+	/* - custom power wells */
 	SKL_DISP_PW_DC_OFF,
-
 	BXT_DPIO_CMN_A,
 	BXT_DPIO_CMN_BC,
-	GLK_DPIO_CMN_C,
+	GLK_DPIO_CMN_C,			/* 19 */
+
+	/*
+	 * Multiple platforms.
+	 * Must start following the highest ID of any platform.
+	 * - custom power wells
+	 */
+	I915_DISP_PW_ALWAYS_ON = 20,
 };
 
 #define SKL_POWER_WELL_STATE(pw) (1 << ((pw) * 2))